springboot报错无法读取配置文件中的属性：Could not resolve placeholder ‘xxxx‘ in value “${xxxx}“

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'config': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'wx.mch.mchId' in value "${wx.mch.mchId}"
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:405) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1420) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1307) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1227) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:884) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:788) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	... 20 common frames omitted
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'wx.mch.mchId' in value "${wx.mch.mchId}"
	at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:178) ~[spring-core-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) ~[spring-core-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:239) ~[spring-core-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:210) ~[spring-core-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties$0(PropertySourcesPlaceholderConfigurer.java:175) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:918) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1248) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1227) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
	... 32 common frames omitted

遇到上面得问题一般都是你在使用@Value标签时的参数没有跟你配置文件（application.yml ,application.yaml和appplication.properties ）里面的配置文件写的格式有问题 如下图：


一定要注意你的缩进和冒号后面有空格 书写格式要规范（建议大家使用yml的配置文件，书写简单明了）